1. Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method for performing for example a resist solution coating process and a developing process for substrates such as semiconductor wafers and glass substrates for liquid crystal displays.
2. Description of the Related Art
In a semiconductor apparatus fabrication process, photolithography technology is used. In the photolithography technology, a resist solution is coated on a substrate such as a semiconductor wafer. With a photo mask, the resist film is exposed and developed. As a result, a desired resist pattern is formed on the substrate.
The photolithography technology is accomplished by a pattern forming system of which an aligner is connected to a coating and developing apparatus. When semiconductor wafers (hereinafter referred to as wafers) are processed, the coating and developing apparatus is composed of a carrier stage, a transfer mechanism, a process block, and an interface station. The carrier stage loads and unloads a wafer carrier. The transfer mechanism takes a wafer from a carrier placed on the carrier stage. The coating and developing apparatus is connected to the aligner. A wafer is transferred to a processing station through the transfer mechanism. The processing station coats a resist film on the wafer. The aligner exposes the wafer. Thereafter, the wafer is returned to the processing station. The processing station develops the wafer. The resultant wafer is returned to the carrier through the transfer mechanism.
After the processed wafer is placed in the carrier, the carrier is transferred from a carrier stage 11 to an inspecting unit disposed in another area this is different from the coating and developing apparatus 1 by an operator or an automatic transferring robot. The inspecting unit inspects the line widths of the resist pattern formed on the wafer, the matching of the resist pattern and the base pattern, the coated irregularities of the resist, the developing defects, and so forth. When the inspected result of the wafer is successful, it is transferred to the next process. When the inspected result of the wafer is NG, it is transferred to a cleaning unit. The cleaning unit dissolves the resist from the wafer so as to restore the wafer to the original state. The resultant wafer is transferred to the pattern forming system again. The pattern forming system performs the similar process for the wafer.
However, since the wafer that has been processed by the pattern forming system is transferred to the external inspecting unit that inspects the pattern of the wafer and then transferred to the next process, the throughput of the system deteriorates. In addition, the wafer should be queued while the inspecting unit is inspecting a wafer whose pattern has been formed by another pattern forming system. Thus, the throughput of the coating and developing apparatus does not advantageously affect the overall process. In addition, when the operator wants to know the inspected result of the pattern, he or she should walk to the place of the inspecting unit. Thus, it is inconvenient to evaluate the recipe of the process corresponding to the inspected result.
An object of the present invention is to provide a substrate processing apparatus and a substrate processing method that allows a substrate to be inspected without a deterioration of the throughput of a coating and developing apparatus and so forth.
Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method that allows a substrate to be easily sample-inspected.
To accomplish the above-described objects, a first aspect of the present invention is a substrate processing apparatus, comprising a cassette station having a holding portion for holding a substrate cassette that contains a plurality of substrates, and a transferring portion for transferring the substrate to and from the substrate cassette placed on the holding portion, a processing station having a substrate processing portion for coating process solution on the substrate transferred from the cassette station, an inspecting station connected to the processing station, the inspecting station having an inspecting portion for inspecting a processed state of the substrate processing portion for the substrate, and a main transfer mechanism for transferring a substrate between the processing station and the inspecting station.
In such a structure, the inspecting station and the processing station are adjacently disposed. In addition, a substrate is automatically transferred between the inspecting station and the processing station. Thus, it is not necessary for the operator to perform the transferring operation. In addition, the transferring time for the wafer is short. Thus, the total operation from the substrate process to the inspection can be simplified. Moreover, since the processed state can be inspected on real time basis, the inspection accuracy is improved. As a result, the total operation time from the process to the inspection can be shortened.
A second aspect of the present invention is an apparatus for coating a resist on a substrate and developing the substrate that has been exposed, the apparatus being connected to an aligner, the apparatus comprising a carrier station having a carrier loading/unloading portion for loading and unloading a carrier that contains a plurality of substrates, and a transferring portion for transferring a substrate to and from the carrier on the carrier loading/unloading portion, a processing station disposed adjacent to the carrier station, the processing station having a coating portion for coating resist on the substrate, a developing portion for developing the substrate that has been exposed, and a main transferring portion for transferring the substrate to the coating portion and the developing portion and transferring the substrate to and from the transferring portion, an inspecting station disposed adjacent to the carrier station, the inspecting station having an inspecting portion for inspecting the substrate, an external carrier holding portion for holding a carrier that contains the substrate that has been processed outside the substrate processing apparatus, and a mode selecting portion for selecting a regular operation mode in which the inspecting portion inspects the substrate processed in the processing station or an inspecting portion dedicated operation mode in which the inspecting portion inspects the substrate processed outside the substrate processing apparatus.
The external carrier holding portion is disposed in the carrier station. The external carrier holding portion is a part of the carrier loading/unloading portion of the carrier station. The inspecting station has an auxiliary transferring portion for transferring the substrate to and from the inspecting portion. An intermediate holding portion is disposed in the carrier station, in the inspecting station, or midway between the carrier station and the inspecting station, the intermediate holding station temporarily holding a substrate. The transferring portion of the carrier station transfers the substrate developed in the processing station and the substrate contained in a carrier on the external carrier holding portion to and from the auxiliary transferring portion through the intermediate holding portion.
According to the present invention, since inspections such as a pattern inspection can be performed in the coating and developing apparatus, the throughput is improved. In addition, when a maintenance operation for the processing station that performs a coating process and a developing process is performed or when the developing process is stopped, the inspecting unit can be independently operated. Thus, a substrate brought from the outside of the system can be inspected.
A third aspect of the present invention is an apparatus that has a similar structure to the above-described aspects. In the third aspect, a second transferring portion is disposed in addition to the transferring portion (first transferring portion) of the carrier station. The second transferring portion transfers the substrate between a carrier on said external carrier holding portion and said inspecting station.
A fourth aspect of the present invention is an apparatus that has a similar structure to the above-described aspects. In the fourth aspect, an external carrier holding portion and an auxiliary transferring portion are disposed in the inspecting station.
A fifth aspect of the present invention is a substrate processing apparatus, comprising a cassette station having a holding portion for holding a substrate cassette that contains a plurality of substrates, and a transferring portion for transferring the substrate to and from the substrate cassette on the holding portion, a processing station disposed adjacent to the cassette station, the processing station having a substrate processing portion for coating process solution on the substrate, and a main transfer mechanism for transferring substrates to the substrate processing portion in the order of those contained in a substrate cassette and transferring the substrates to and from the transferring portion in the order of those contained in the substrate cassette, an inspecting portion for inspecting the processed state of the substrate processing portion for the substrate, an inspecting substrate holding portion for holding an inspecting substrate that has been processed outside the substrate processing apparatus and that is inspected in the inspecting portion, a substrate holding portion for holding substrates that have been processed in the substrate processing portion and that are later than the inspecting substrate in the substrate cassette in the order of those contained therein, and a main transfer mechanism for transferring the substrate that has been processed in the substrate processing portion to the inspecting substrate holding portion and the substrate holding portion.
In such a structure, since the substrate processing apparatus is provided with the inspecting portion, it is not necessary to convey a substrate for a longer distance than the case that the inspecting portion is disposed as an external apparatus. Thus, the transferring time is short. As a result, the throughput of the system is improved.
The above-described apparatus performs a substrate processing method, comprising the steps of transferring a plurality of substrates contained in a substrate cassette to a substrate processing portion in the order of the substrates contained in the substrate cassette and coating process solution on the substrates, unloading a substrate processed in the substrate processing portion from the substrate processing portion, transferring an n-th (n is any integer equal to or larger than 1) inspecting substrate that is contained in the substrate cassette and that is unloaded from the substrate processing portion to an inspecting portion and causing the inspecting portion to inspect the processed state of the substrate processing portion, transferring substrates later than an inspecting substrate to a substrate holding portion and causing the substrate holding portion to hold the substrates in the order of the substrates contained in the substrate cassette until the inspecting portion completes the inspection of the inspecting substrate when the process time period of the inspecting portion is longer than the transferring intervals of substrates transferred from the substrate processing portion, unloading the inspecting substrate that has been inspected in the inspecting portion from the inspecting portion, and unloading the inspecting substrate from the inspecting portion and then unloading the substrates held in the substrate holding portion therefrom in the order of the substrates contained in the substrate cassette.
According to the present invention, when a substrate that has been processed in the substrate processing portion is sample-inspected and the process time of the inspecting portion is longer than the transferring interval of substrates to the substrate processing portion, while an inspecting substrate is being inspected, substrates that are not inspected are queued in the substrate holding portion. Thus, without need to provide a complicated sample-inspecting transferring program, substrates can be returned to the original cassette in the order of those contained therein.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings.